Activating Vitamin D new therapy for diabetes, cancer

Researchers from the San Diego-based Salk Institute reported on Thursday in the journal Cell a potential new approach for treating diabetes by protecting beta cells.

The investigators identified an unexpected source: vitamin D. Vitamin D in cells and mouse models, in combination with a compound that activates its receptors, proved beneficial in treating damaged beta cells.

The study provided new insights about gene regulation that could be applied to developing treatments for other diseases, including cancer.

Beta cells in the pancreas produce, store and release the hormone insulin. When beta cells become dysfunctional, the body cannot make insulin to control blood sugar and levels of glucose can rise to dangerous, even fatal, levels.

"We know that diabetes is a disease caused by inflammation," said the paper's senior author Ronald Evans, Salk's March of Dimes Chair in Molecular and Developmental Biology. "In this study, we identified the vitamin D receptor as an important modulator of both inflammation and beta cell survival."

Using beta cells created from embryonic stem cells, the investigators identified a compound called iBRD9, which helped enhance the activation of the vitamin D receptor when it was combined with vitamin D to improve the survival of beta cells.

The team conducted a screening test to look for compounds that improved the survival of beta cells in a dish. Then they tested the combination in a mouse model of diabetes and showed that it could bring glucose back to normal levels in the animals.

Combining the new compound with vitamin D allowed certain protective genes to be expressed at much higher levels than they are in diseased cells, according to the investigators.

"Activating the vitamin D receptor can trigger the anti-inflammatory function of genes to help cells survive under stressed conditions," said Michael Downes, a Salk senior staff scientist and co-corresponding author.

"In this study, we looked at diabetes, but because this is an important receptor it could potentially be universal for any treatments where you need to boost the effect of vitamin D," said Ruth Yu, a Salk staff researcher and one of the study's authors.

"For example, we are especially interested in looking at it in pancreatic cancer, which is a disease that our lab already studies," said Yu.

The investigators said that, although the new compound did not appear to cause any side effects in the mice, further testing is needed before clinical trials can begin.